You don't have to accept a third party booking. So you can tell the guest to cancel. Or you can call Airbnb and ask them to cancel for you.
If the guest goes on line and tells Airbnb that 'you' want to cancel then Airbnb will send an automated request to you and if you accept the cancellation then it will penalize you.
So the guest either needs to cancel outright or you need to call and get it cancelled. Don't accept a cancellation that indicates your listing is unavailable because of something on your end.
You might want to limit your listing to women and couples until you are more used to the platform. You can do that because you live there.
You can avoid dealing with third party bookings by prominently featuring NO THIRD PARTY BOOKINGS near the top of your listing. In your HOUSE RULES put that the booking guest MUST be present to check in and that others will not be admitted.
Or, when discussing with the guest ask the question: will you personally be staying? Are you traveling alone or with a companion or group? Ask this before you approve the stay. If they say no to the first question or if the number of people on the reservation request does not match the answer to the second question, then decline the reservation and tell them to rerequest when the request is correct. You can explain that the booking guest must check in and all guests must be declared upon booking, also that no visitors or other guests may enter at any time.